Biofilms are formed by bacteria in aqueous environments, which interact with the surfaces to which they are exposed to form surface colonies and films which continue to adhere to the surfaces and grow. More specifically, the bacteria produce extensive exopolysaccharide or extracellularpolysaccharide polymers (EPS or ECPS) that keep them attached to the surfaces and form living films thereon, frequently called “biofilms”. These biofilms can be formed on a variety of surfaces, including human tissues, medical devices, dental office equipment, counters, pipes and the like. Biofilms coat the surface and become a living colony for the continued proliferation of microorganisms, and protection of the microorganisms from removal and from conditions which might destroy the microorganisms. Biofilms are much more difficult to remove than bacteria in the plaktonic state, and the bacterial contamination of the biofilms from surfaces or tissue are thus much more difficult to eliminate. Biofilms in this state are extremely resistant to many antibiotics and biocides.
When present on human tissues, biofilms can cause chronic conditions from which many persons today suffer. Such conditions include rhinosinusitis, where biofilms are attached within the nasal passages and sinuses, infiltrating and protecting the underlying pathogenic bacteria and preventing them from being dislodged from their surfaces, and immune system disorder symptoms where biofilms have coated bodily tissues and surfaces such as joints or nerves in a manner which impairs the normal function thereof. Additionally, enclosure of implants or surgical appliances with biofilms may lessen their effectiveness.
Previous strategies for removal of biofilms have focused on both removal and destruction of bacteriums in the biofilm. Products for such cleansing, such as biocides, disinfectants and the like for use in such areas may be caustic and employ agents that can damage human skin, and especially non-dermal human tissues upon contact and therefore cannot be used to remove biofilms from human orifices and tissues. Methods of cleaning and disinfecting such surfaces effectively for biofilms may also involve large dosages, and long periods of contact with the surface, e.g., soaking biofilm contaminated surfaces for 12-24 hours, which is impractical for preoperative and postoperative situations and for many surfaces and devices as well as being impossible for use on or with most contaminated human tissues.
Methods of removal of biofilms from human tissues such as sinuses to flush them from the system have included mechanical debridement of the tissues and/or surgical opening of sinuses to allow for drying and subsequent removal of the biofilm. Such methods damage the tissues and require healing periods, and further present opportunities for new bacteria to contact the surfaces and cause infections and new placement of biofilms. Antibiotics have also been attempted but, while they are effective against plaktonic bacteria, they have been only marginally effective against biofilms, and then only when administered in large dosages, which may be otherwise undesirable for the patient or living tissues.
It would be desirable to have a solvating system for removing biofilms from human tissues which would meet biocompatibility requirements for contact with human tissue, and yet be effective in removal of such biofilms from tissues and bodily orifice linings such as nasal orifices, sinuses, oral tissues, for removal from implants or other appliances attached to bodily tissues and the like. Such desirable solvating systems would preferably be effective in small dosages for short periods of application. It would also be desirable for such solvating system to be further useful to dislodge biofilms attached to non-tissue surfaces in environmental locations such as medical devices and water systems, dental equipment and the like.
It has now been discovered that a solvating system comprising an alkali, metallic, or metal ion sequestering agent and a solvent or surfactant is surprisingly effective in removal of biofilms such as polysaccharides from human tissue while being gentle enough for application directly onto such tissues.